<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <!-- 新 Bootstrap4 核心 CSS 文件 -->
    <link rel="stylesheet" href="https://cdn.staticfile.org/twitter-bootstrap/4.3.1/css/bootstrap.min.css">

    <!-- jQuery文件。务必在bootstrap.min.js 之前引入 -->
    <script src="https://cdn.staticfile.org/jquery/3.2.1/jquery.min.js"></script>

    <!-- bootstrap.bundle.min.js 用于弹窗、提示、下拉菜单，包含了 popper.min.js -->
    <script src="https://cdn.staticfile.org/popper.js/1.15.0/umd/popper.min.js"></script>

    <!-- 最新的 Bootstrap4 核心 JavaScript 文件 -->
    <script src="https://cdn.staticfile.org/twitter-bootstrap/4.3.1/js/bootstrap.min.js"></script>
    <title>css布局--按钮（11.16）</title>
</head>
<body>
    <div class="container">
        <div class="row">
            <div class="col-3 bg-success">
                <!-- active激活 -->
                <button class="btn btn-primary btn-block active" >登录</button>
            </div>
            <div class="col-3 bg-success">
                <!-- disabled禁用 -->
                <button class="btn btn-primary btn-block disabled">取消</button>
            </div>
            <div class="col-3 bg-success">
                <button class="btn btn-primary btn-block">登录</button>
            </div>
            <div class="col-3 bg-success">
                <button class="btn btn-primary btn-block">取消</button>
            </div>

        </div>
    </div>
    <div class="container">
        <h2>按钮使用</h2>
        <button class="btn">基本按钮</button>
        <a class="btn btn-primary btn-block" href="#">主要按钮</a>
        <a class="btn btn-primary" href="#">主要按钮</a>
        <button class="btn btn-outline-primary">主要按钮</button>
        <button class="btn btn-secondary">次要按钮</button>
        <button class="btn btn-success">成功按钮</button>
        <button class="btn btn-info">信息按钮</button>
        <button class="btn btn-warning">警告按钮</button>
        <button class="btn btn-danger">危险按钮</button>
        <button class="btn btn-dark">黑色按钮</button>
        <button class="btn btn-light">浅色按钮</button>
        <button class="btn btn-link">链接按钮</button>
        <!-- <button class="btn btn-danger">危险按钮</button>
        <button class="btn btn-danger">危险按钮</button> -->
        

    </div>

    <!-- 响应式--图像 -->
    <div class="container-fluid">
        <img  class="img-fluid rounded"src="img/img2.jpg">
        <img class="img-fluid rounded-circle" src="img/img2.jpg">
        <img class="img-fluid img-thumbnail" src="img/img2.jpg">
    </div>
</body>
</html>